Obsolete electronics replacement: from reverse engineering to a working board in your equipment
When a board or module in your equipment can no longer be bought or repaired, Micro Digital Engineering finds out how it works, restores the documentation where it is needed and develops a working replacement. Replacement prototypes are assembled, brought up and tested in-house, first on the bench and then in your equipment, against compatibility requirements agreed with you.
Confidential task? We sign an NDA before you share technical files.
What can we do when an industrial control board is no longer manufactured?
First establish what the board does in the equipment and what is still available: schematics, spare units, firmware, components. Then choose the result you need — technical information about the board, a documented design, or a working replacement. The three are different pieces of work with different deliverables, and a project can stop after any of them.
Reverse engineering, schematic reconstruction and functional replacement
| Work | Question it answers | What you receive | Details |
|---|---|---|---|
| Reverse engineering | How does the board work, and what does it depend on? | Analysis of functions, interfaces, critical components, obsolescence risks and the options for replacement | PCB reverse engineering |
| Schematic reconstruction | What exactly is on the board? | Reconstructed schematics, bill of materials and, when needed, PCB design data for repair or remanufacturing | Schematic and design data reconstruction |
| Functional replacement | What will work in the equipment instead of it? | Replacement boards tested in the equipment, with design files and a manufacturing package | This page and compatible replacement boards |
If the board’s behaviour depends on a microcontroller or programmable logic, firmware recovery and migration is part of the work.
Replacement routes
Remanufacture from reconstructed data
When the original components are still available, the board can be rebuilt from reconstructed schematics and PCB data, with minimal changes.
Form, fit and function replacement
The replacement fits the existing housing, mounting and connectors and behaves like the original at its interfaces, while the internal design uses current components. See compatible replacement boards.
Functional redesign
The function is preserved but the design may change: different dimensions, connectors or architecture, agreed with you. This is the route when the original concept itself depends on parts that no longer exist.
When you need this
- A control or interface board has failed and spare parts are no longer available.
- Components on the board are discontinued, so it cannot be repaired or remanufactured as it is.
- You want to keep proven equipment in service instead of replacing the whole machine.
- Repeated repairs of the same module cost more than a replacement.
- You need documentation for a board that was never documented, to repair or service it.
What’s included
Assessment of the original board and its role in the equipment, reverse engineering to the depth the chosen route requires, definition of the functions, interfaces and compatibility requirements, component availability review, schematic and PCB design of the replacement, PCB fabrication through a manufacturing partner, in-house prototype assembly and bring-up, bench tests, verification in the equipment and documentation for repeat manufacturing.
PCB fabrication is performed by specialised manufacturing partners. Prototype component assembly, bring-up, debugging and verification are carried out in-house by our engineering team.
How compatibility is verified
Compatibility is defined before design starts: which signals, voltages, timing, connectors, dimensions and behaviours must be the same as the original, and what may differ. The prototype is first tested on the bench against these requirements and then in the equipment, under acceptance criteria agreed with you.
What you receive
| Deliverable | Format | How it is checked |
|---|---|---|
| Analysis of the original board | Document: functions, interfaces, critical components, risks | Review with you |
| Compatibility requirements | Document: functions, interfaces, signals, dimensions | Review and written approval |
| Reconstructed or redesigned schematics and PCB | Design files, PDF schematics | Design review |
| Bill of materials with available components | Spreadsheet with manufacturer part numbers | Availability check at handover |
| Firmware, when needed | Agreed format, see firmware recovery | Tests in the equipment |
| Replacement prototypes, assembled in-house | The agreed number of boards | Bench tests, then tests in the equipment |
| Test report | Document | Results against the acceptance criteria |
| Manufacturing package | Gerber or ODB++, assembly drawings, BOM | Review against the manufacturer’s requirements |
How the project runs
- You confirm that you own the equipment or are authorised to maintain it; the board and its role in the equipment are assessed.
- The board is analysed to the depth the chosen route requires.
- Compatibility requirements and acceptance criteria are agreed in writing.
- Schematics are reconstructed, or the replacement is redesigned with available components.
- The bare PCBs are fabricated by a manufacturing partner; the prototypes are assembled and brought up in-house.
- The prototypes are tested on the bench, then in the equipment.
- You accept the replacement; the design files and manufacturing package are handed over.
See how we work.
What to send us
- Photos and, if possible, samples of the board; a spare unit makes analysis easier.
- Equipment documentation and the board’s role in it.
- Known failures and their history.
- Interfaces and connected equipment.
- Confirmation that you own the equipment or are authorised to maintain it.
Common questions
Can you work without schematics?
Yes. In that case the work starts with reverse engineering of the existing board.
Can we order only reverse engineering or only the schematics?
Yes. Each result can be ordered as its own stage. Many projects start with the analysis, and the decision on a replacement is made after it.
Will the replacement be identical to the original?
Not necessarily. The compatibility requirements define what must stay the same at the interfaces and in the equipment, and what may differ inside the board.
Is it legal to reverse engineer and replace the board?
We work on equipment that you own or are authorised to maintain, and we ask you to confirm this at the start. We do not reproduce third-party products for resale. If rights are unclear, discuss them with your legal adviser before the project starts.
Can the replacement be manufactured in small batches?
Yes. The manufacturing package allows repeat production, and the manufacturing route and quantities are agreed in the project.
What if the board contains a microcontroller with firmware?
Then the firmware is assessed as part of the project: extraction of the existing image or a new implementation of its functions. See firmware recovery and migration.
Related services
- PCB reverse engineering — when there are no schematics.
- Schematic and design data reconstruction — when documentation is the goal.
- Firmware recovery and migration — when the behaviour depends on firmware.
- Compatible replacement boards — when form, fit and function must stay the same.
- Test benches — for testing replacement boards before installation.
Discuss a replacement
Send photos of the board, a description of the equipment and what has failed. We will suggest the route and the first stage.
Confidential task? We sign an NDA before you share technical files.